Role of IFN-g+874 T/A single nucleotide polymorphism in the tuberculosis outcome among Brazilians subjects

• Published in: Molecular biology reports Vol. 35; no. 4; pp. 563 - 566
• Main Authors: Amim, Lucia HLV, Pacheco, Antonio G, Fonseca-Costa, Joseane, Loredo, Carla S, Rabahi, Marcelo F, Melo, Maria H, Ribeiro, Fernando CV, Mello, Fernanda CQ, Oliveira, Martha M, Lapa e Silva, Jose R, Ottenhoff, Tom H, Kritski, Afranio L, Santos, Adalberto R
• Format: Journal Article
• Language: English
• Published: 01.12.2008
• Subjects: Mycobacterium tuberculosis
• ISSN: 0301-4851; 1573-4978
• DOI: 10.1007/s11033-007-9123-1

Several genetic cytokine gene variants have been associated with host susceptibility to infectious diseases, including tuberculosis. Based upon the importance of IFN-g in protective immunity against Mycobacterium tuberculosis, and the functional role of the IFN-g+874T/A single nucleotide polymorphism in IFN-g production, we genotyped 93 Brazilian tuberculosis patients and 266 asymptomatic health care workers, including 150 individuals with a positive tuberculin skin test, and analyzed the possible association of the +874A low IFN-g producer allele with tuberculosis occurrence. Using multivariable logistic regression models, genotype and allele frequencies of the mutant + 874A (low IFN-g producer) allele were significantly associated with tuberculosis disease. Heterozygous carriers had a 25% increased chance, while individuals presenting the A/A homozygous genotype had an over two-fold risk of having active tuberculosis (95% CI, 1.16-5.91, P=0.03). Despite the mixed ethnicity observed in Brazilian populations, the present data agree with observations reported in other populations and thus demonstrate that the functional +874T/A IFN-g gene polymorphism is associated with tuberculosis in different populations.